Hi there! I understand that when you open the Investing.com app on your iPhone (iOS 18.5), it just shows a black screen and doesn't load. Let's dig a bit deeper to help fix this.

First, could you tell me if you've already tried any of these common steps?
- Closing the app completely and reopening it
- Restarting your iPhone
- Switching between WiFi and mobile data to check connectivity

If you haven't done those yet, let's start with this checklist:

1. Force close the app: Swipe up from the bottom (or double-click the Home button if your iPhone has one) to bring up the app switcher, then swipe the Investing.com app off the screen to close it. Then, reopen the app.

2. Check your internet connection: Sometimes switching from WiFi to cellular data (or vice versa) can refresh the network connection.

3. Restart your iPhone: Press and hold the side button and volume up or down button until the slider appears, then slide to power off. Turn your device back on to refresh all processes.

4. Update the app: Make sure the Investing.com app is updated in the App Store. An outdated app could cause loading issues.

5. Clear app cache or reinstall: On iOS, there's no direct cache clear option, so uninstall the app by pressing its icon and choosing "Remove App," then reinstall it from the App Store.

Could you try these and let me know if the black screen persists? If it does, we can look into advanced solutions like checking account status or server-side issues.

Are you able to proceed with this?